Polyopia

POLYOPIA (literally multiple vision), such a condition of the eyes in which the fixed object seems not single but multiple. The basis of this phenomenon b. ch. lies in certain specific conditions of refraction of light rays, caused mainly by the lens. The lens consists of a number of sectors differing from each other in their refractive index, although this difference is small. This difference, which in different individuals is expressed to varying degrees, in itself can be the reason for several images of the fixed object to arise on the retina. Usually, however, with a normal pupil width and normal accommodation, R. almost never manifests. It becomes noticeable only when, due to some disease or after atropinization, the pupil dilates and accommodation is paralyzed. R. can be caused by the initial stage of cataract development, in which sometimes the appearance of lens opacities is preceded by the formation of cracks in the lens. Due to this, a whole series of new reflecting surfaces arises in the lens, which give R. Sometimes R. is caused by polycoria, i.e. the presence of not one but several pupil openings in the iris as a result of developmental anomaly. In addition to all these cases where R. has an organic basis, in hysteria R. of functional origin is observed. It is caused by irregularity in the work of accommodation, differs in its inconstancy, is often accompanied by macro- and micropsia, and yields to treatment by suggestion.